+PH/37 Exim used to check for duplicate addresses in the middle of routing, on
+ the grounds that routing the same address twice would always produce the
+ same answer. This might have been true once, but it is certainly no
+ longer true now. Routing a child address may depend on the previous
+ routing that produced that child. Some complicated redirection strategies
+ went wrong when messages had multiple recipients, and made Exim's
+ behaviour dependent on the order in which the addresses were given.
+
+ I have moved the duplicate checking until after the routing is complete.
+ Exim scans the addresses that are assigned to local and remote
+ transports, and removes any duplicates. This means that more work will be
+ done, as duplicates will always all be routed, but duplicates are
+ presumably rare, so I don't expect this is of any significance.
+
+ For deliveries to pipes, files, and autoreplies, the duplicate checking
+ still happens during the routing process, since they are not going to be
+ routed further.
+
git://git.exim.org / users / heiko / exim.git / blobdiff